1. Field of the Invention
This invention relates to a method and apparatus for controlling a solid fuel burning furnace which controls and automatically maintains the burning in the furnace using a solid fuel such as coal, powdered coal and coke. The invention includes the case of a stove to warm up room air with a direct load and a boiler to heat water with a direct load for room heating and supplying heated water.
2. Description of the Prior Art
Conventionally, in this type of burning furnace, a small coal burning boiler for instance, only the water temperature in the boiler is safeguarded with a temperature sensor but the operation of the fire grate is manually performed by measuring a temperature with a thermometer or sensing it with the skin. To maintain the desired heat generating energy, manual vigilance is required. Because of difficulties in accurately knowing the burning condition, the prior art has had such problems as unburnt fuel being discharged when the timing of the operation of the fire grate is too early or the grate being operated too often to meet a rapid change in a room temperature such as at the time of opening and shutting of a door or window, and the burning source is extinguished when the timing is too late.
The present inventors have performed experiments and research and found that time elements T.sub.1 and T.sub.2 are an important factor to solve these problems, and, based on their knowledge, have accomplished this invention.